- All-purpose flour, for dusting
- 1/2 pound frozen puff pastry, thawed
- 2 tablespoons extra-virgin olive oil
- 3 medium leeks, white and tender green—halved lengthwise, thinly sliced crosswise and rinsed well
- 1 teaspoon finely chopped thyme
- Salt and freshly ground pepper
- 1/2 pound Gruyère cheese, coarsely shredded (2 cups)
- 3 ounces thinly sliced prosciutto
- Preheat the oven to 475°. On a lightly floured surface, roll out the pastry to a 13-inch square. Fold the corners in and lightly roll the pastry into a rough round. Transfer to a baking sheet; refrigerate.
- In a large skillet, heat the olive oil until shimmering. Add the leeks and thyme, season with salt and pepper and cook over moderate heat, stirring occasionally, until softened, about 5 minutes.
- Sprinkle half of the cheese over the pastry, leaving a 1-inch border. Spread the leeks over the cheese. Cover with the prosciutto; sprinkle on the remaining cheese. Season with salt and pepper. Fold up the tart edge to form a rim and bake for 20 minutes, until golden and bubbling. Blot any excess fat with a paper towel. Cut the tart into wedges.
A berry-flavored California Pinot Noir, such as one from Carneros.